Effect of Ramadan Fasting on Keratometry Readings and Tear Film Stability: Implications for Refractive Surgery Planning

Abstract

Background: Ramadan fasting is accompanied by physiologic changes which can affect tear film parameters and corneal parameters. Fasting induced changes effect factors like keratometry and tear film stability are significant factors that are needed in refractive surgery planning.
Objective: To assess the keratometry and tear film stability changes during fasting and their implications for surgical planning.
Methodology: The is quasi-experimental study was carried out in the Eye OPD of Chaudhary Muhammad Akram Hospital on 50 healthy fasting subjects aged 20-25 years. Ocular parameters were measured with and without fast. Keratometry readings (K1 and K2), Tear Break Up Time (TBUT) and Schirmer's test were performed. Data were analysed with SPSS version 25 and Wilcoxon signed rank test was applied to compare the measurements.
Results: The study showed a significant rise in the corneal curvature in fasting period. Mean K1 increased from 42.37 ± 1.13 D to 43.15 ± 1.07 D during non-fasting and fasting (p < 0.001), while mean K2 increased from 43.01 ± 1.08 D to 43.62 ± 1.06 D(p < 0.001). Fasting had a significant effect on decreasing the tear film stability, as indicated by a decrease in TBUT from 11.46 ± 3.97 seconds to 10.74 ± 4.51 seconds(p = 0.020). Also Schirmer's test values significantly reduced on fasting(p < 0.001).
Conclusion: The fasting period during Ramadan appears to have a profound impact on the cornea and tear film stability, potentially impacting on the planning of refractive surgery and the accuracy of the ocular biometry.